Port-Orford-Cedar Mapping within the Biscuit Fire
Port-Orford-cedar (POC)
Chamaecyparis lawsoniana
Frank Betlejewski, USDA Forest Service, Forest Health Protection,
Southwest Oregon Forest Insect and Disease Service Center,
Central Point OR 97502
POC is native to an area along the Pacific
Coast from Coos Bay, Oregon, to the mouth
of the Mad River near Arcata, California.
Its range extends from the coast to about 50
miles inland. There is also a small disjunct
population in the Scott Mountains of California.
Phytophthora lateralis (PL)
PL is a virulent, non-native root pathogen. It was introduced
into the native range of Port-Orford-cedar in the early 1950s
and its place of origin is unknown. It readily kills POC of all
ages that are growing on sites favorable for infection. PL is
spread via water or soil. A typical spread scenario involves
infested soil being transported into an un-infested area on a
vehicle or piece of equipment. The infested soil falls off of the
vehicle and the pathogen first infects POC near the site of
introduction. New spores from that infection are then washed
downhill in surface water infecting additional hosts. This is
especially lethal along drainages and creeks where infested
water is channeled and flows near concentrations of healthy
POC.
Phytophthora lateralis
Resting spores (chlamydospores)
magnified 100 times
Characteristic crown discoloration as
a result of PL. Less than 1% of all POC
are considered to have complete
resistance to the pathogen
Upper North Fork of Silver Creek before and after the Biscuit fire.
2004
1998
Some streamside areas with POC experienced a
less severe fire event and had greater survival.
After a crown fire on serpentine soils,
POC survivors adjacent to a spring.
Biscuit Fire Data Sheet
Project Costs (through 2006)
Biscuit Fire
2002 and 2005 Aerial Photo Mapping Of
Positive air photo transparencies (1,472) $48,576
Port-Orford-cedar
July 13 – November 9,
2002
Photo transparencies scanned onto
740 CDs
$27,620
499, 965 acres
Service contract (photo interpretation
and mapping)
$25,840
Service contract (create GIS layer)
$23,542
Labor estimate (Federal employees)
$11,704
2004 Air Photo Flight
$7,000
Total
$144,282
Acres Inventoried
499,965
Cost per Acre
$0.29
Polygon Attribute Table
1)
2002 or 2004 Photo & Flight Line:
2)
Polygon #
3)
Root Disease?
4)
Live POC % Canopy Closure
5)
Survey Date
6)
Est. # Live POC By Size Class
7)
Est. # Dead POC By Size Class
8)
Field Verification Level
9)
Remarks
POC and PL Pre-Biscuit
Oregon: 471,130 acres
California: 28,835 acres
The Biscuit Fire had a stand replacement event on
about 46,000 acres occupied by healthy POC and 900 acres
infested with PL. This is about 48 percent of the inventoried
acres with POC that existed before the fire.
POC and PL Post-Biscuit
POC acres: 23,282
POC acres: 89,880
(25.9% of pre-fire acres)
PL acres: 835
PL acres: 3,022
(27.6% of pre-fire acres)
Represents 29% of all
Reduced acres are a function
of the fire and more precise
mapping.
POC on Federal lands.
Landscape Patterns
Post-fire, POC is more strongly associated with riparian areas.
This is a function of the fire and more precise mapping.
Areas of serpentine soils that still have POC tended to burn with
greater severity that non-serpentine soils with post-fire POC.
In Oregon, approximately 34% of POC acres on serpentine soils
(3,958 of 11,824 acres) were characterized by dead trees with or
without needles. This compares to 13% of POC acres on nonserpentine soils (1,571 of 12,037 acres) characterized by dead
trees with or without needles.